Obese and stuck on a deserted Island...

I have often wondered what would happen to an obese person marooned on a desert island. Would they die of starvation before they had lost all their extra weight, or would they die of starvation and still be obese? If a 550lb man and a 200lb man were both marooned at the same time, who would die of starvation first? (Assume they have as much fresh water as they need, and yet no real way of getting food, no fish etc…)

The 550 lb man might well expire first as 550 lb people are usually in pretty poor health overall, and the stress of starvation and hauling an extra 350 lbs of fat around to hunt for food or tend to other survival necessities under a hot sun might finish them off before they trimmed down to a healthier weight.
If the 550 lb man was strong enough to physically whether the basics of island survival he would probably survive longer.

As to what the break point is of how long you can survive on human body fat sans anything else I have no clue. Without any food I would guess that the 550 man would die before he got truly skinny as fat is a good emergency store but is not a “perfect” food and the body would also metabolically consume the muscles and internal organs for non-fat nutrients which would/could kill you before you got lean and mean.

sigh… whether=weather

This question reminds me of when I asked how long a person could survive eating their own self & or
recycling body fluids. I was told I needed a biochemist but never found one.

Okay, puttering around on Google, “human body starvation symptoms famine” and combinations thereof, turned up some stuff.



So the OP person’s metabolism would slow down, he’d start living off his stored fat, and only after he’d used up all his stored body fat and looked like a “starving person” would he then die.

One thing I started thinking about when one of my (chubby) teachers said “in a famine the people capable of building up reserves would live longer than skinny people” was well to what degree can such people actually mobilize those reserves ? Anyone who has dieted or known others who tried realizes very fast that people’s metabolic rates are all different, and that almost no two people will lose weight at the same rate.

In considering who’d last longer: a 200lb man or a 550lb man, another monkey wrench that ought to be thrown into the equation is that you can’t assume that they’ll be burning up their body fat at the same rate. The fatter guy could perhaps not be very efficient at using all that body fat, and consequently start getting weak, sick, and/or dead before he actually burned it all off… or not… ???

I think various assorted vitamin deficiency maladies would make life miserable for somebody who is just living on body fat. Scurvy, while possibly not fatal by itself, might lead to other opportunistic infections that would be hard to fight off on a desert isnald.


Whichever vitamin prevents dyslexia, I’m obviously deficient.

This is along the lines of what I was thinking. I thought that the fat person might die of some nutritional deficiency before they had been able to burn off all the fat. It looks like a race to see what is going to be fatal first.

I am now going to investigate how long such a thing might take. e.g. How fast would someone loose weight in a starvation situation. I assume the fat person would loose weight more quickly than the avg weight person if only becasue their body would be able to be less efficient for a longer period of time, plus they have the extra mass to keep alive. Just to throw out numbers, the normal guy might loose 5lbs a week, and the fat guy might loose 7 or 8, but by the time the fat guy dropped 350lbs he would be loosing weight more slowly… that is, if he was still alive…

Did you ever read that short story by Stephen King about a guy who is ship wrecked on an island with no food, but with tons of heroin? He doesn’t do drugs himself, and for awhile he is able to hunt birds and eat. One day he then breaks his ankle and has to amputate it with a knife when it gets infected. To kill the pain he snorts a bunch of drugs. While he is recovering from his surgery he can’t hunt so he ah, eats his foot that he just cut off…he keeps doing drugs for the pain and he is still hungry so he cuts off the other foot…you can see where this is going… :eek:

The Stephen King story is “The Survival Type,” if I remember correctly. What I am thinking about, reading this thread, is that, even though the OM’s fat reserves would provide him with enough energy to run his body systems, he would be deficient in potassium, sodium, and other vitamins and minerals that he needs.

If there is plenty of fresh water on the island, but no food, it is obvious who could survive longer. The 200lb man, unencumbered by blubber, could kill the OM with a rock or stick for use as food.

Anyone read Neal Stephenson’s Cryptonomicon? We could use the computer program that calculates energy and nutrient use and production based on diet, activity, and body size.


Yep, that’s the story. I couldn’t remeber the title. Thanks!
So what will kill him first? Running out of fat or running out of minerals vitamins etc…?

They would all call him “Piggy”, then steal his glasses in order to start campfires?


About nutrition: be aware that the ammonia in urine comes from protein breakdown… proteins are constantly cycling through your system. If all you have is your stored fat, then you have plenty of lipids/carbos, but suffer from a massive protein deficiency.

Ancient shipboard starvation issue: vitamin C deficiency (scurvy) was the main killer.

Without food, I’d be a close bet between protein deficiency getting you before the vitamin deficiencies did. If you were eating plant material (seaweed, scrub growth, etc.) you could hold off both problems.

On lifeless desert islands, the inhabitants get washed into the sea by the first storm to come along. Larger islands develop lots of plant life, and tropical islands tend to have lots of edible plants and insects. Your lifeless, storm-proof desert island would have to be a tall rocky crag in the far north.

Probably blood loss, about five minutes after cutting off the first foot.

Wouldn’t either acidosis (sp?) or ketosis (sp?) be an element in this scenario? I always thought the danger of fasting was the big drop in your blood’s pH as fat metabolism occurs, potentially putting your life in peril.